Fukushima, Japan -- A 65 year old who was doing decontamination work at the Fukushima Nuclear Plant was diagnosed with leukemia recently. It was determined that the leukemia was a direct result of his work at the plant.

What is worrying workers is that the worker had only been working at the plant for 1.5 years and had 23 mSv of accumulated radiation exposure. However, the exposure limit for workers, set by the Health, Labor, and Welfare Ministry was set at 50 mSv a year. In addition, if someone becomes ill and has exposure of more than 5 mSv, it is considered an industrial accident and the victim will be compensated. Why is there a 10x difference in exposure between what is considered "safe" and what is considered an industrial accident?